The truth of the matter, however, is much more complicated: most of our deepest beliefs depend ultimately upon the acceptance of some presuppositions for which we have absolutely no evidence (things like causality, induction, identity, substance, the self, etc.), since these are the assumptions we use in order to make sense of the things for which we do have evidence.
This is ultimately one of the key differences between science and philosophy (and why my love tends more to the latter than to the former): science depends upon the acceptance of certain concepts, and takes these as its starting point, while philosophy tries to make sense of these concepts, and constantly questions them and challenges them in an effort to help us improve the quality of our discourse, as well as understand the limits of our substantive claims about reality.
The Scottish philosopher David Hume was an iconoclastic master at peering beneath the surface of our categorical preconceptions. It is deliciously ironic, therefore, that he showed in the process that our knowledge is, quite literally, superficial: our perception is limited to the sensible qualities of objects, and not to their secret powers, and if that's true, then we can kiss the ideas of cause and effect, identity and induction good-bye... In the following delightful conversation, Bryan Magee and John Passmore discuss the importance, subtlety and influence of this incredible genius.
For more of these fascinating conversations about the Masters of Philosophy, check out the Bryan Magee tag.